Diagnosis Of Plasma Cell Dyscrasias Research Articles

Starry Sky Appearance of an Amyloid Heart in Plasma Cell Dyscrasias

We report an extremely rare case of amyloid heart with classical “Starry Sky” appearance in echocardiography in a 52-year-old male presenting with systemic amyloidosis secondary to plasma cell dyscrasias. Interestingly, patient presented with diffuse myalgia unresponsive to traditional nonsteroidal anti-inflammatory drugs with effort dyspnea New York Heart Association Class II secondary to Grade II diastolic dysfunction of stiff myocardium infiltrated with amyloid protein. A starry sky pattern of an amyloid heart led to the retrospective diagnosis of plasma cell dyscrasias with presence of 30% plasma cells in bone marrow biopsy without the presence of M band in serum electrophoresis.

Cold Agglutinin Disease: Challenges in the Serological Workup and Management

Abstract Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia associated with autoantibodies that react mainly in the cold. CAD can interfere with immunohematology tests. We report two cases of CAD presented initially as blood grouping discrepancy leading us to further workup. Case I was a 61-year-old female with symptoms of weakness, bone pain, and difficulty breathing with laboratory findings of high cold agglutinin titers of 1:1024. Bone marrow aspirate revealed a mixture of >30% plasma cell and plasma blast. Bone marrow biopsy revealed an interstitial, focal, and nodular pattern of involvement by plasma cells, leading to the diagnosis of plasma cell dyscrasias. Case II analyzed was benign CAD with cold agglutinin titers of 1:64, with no other abnormality. Both patients were managed successfully. We report serological and clinical findings of two CAD cases with similar serological findings but different clinical outcomes.

Clinical and Laboratory Indications for Serum Protein Electrophoresis Testing in US Veterans: A Retrospective Cohort Study

Introduction: Serum Protein Electrophoresis (SPEP) is a frequently ordered diagnostic test when there is suspicion of plasma cell dyscrasia, based on clinical or laboratory abnormalities. This study describes the demographic characteristics of US Veterans who underwent SPEP testing, evaluates the distribution of clinical and laboratory abnormalities, and their influence on SPEP test ordering by Veteran Health Administration (VHA) providers. Methods: The study employed a retrospective cohort design utilizing national data from the VHA. We included Veterans aged 50-65 years who had a total protein test performed at any time. Veterans who were dually enrolled in VHA and Medicare were excluded because of the unavailability of laboratory data in Medicare. An ordered SPEP was defined by Current Procedural Terminology codes of 84165 or 83883. Multivariable logistic regression was performed to examine the association of SPEP testing with clinical and laboratory indications, including, chronic kidney disease, anemia, pathologic fractures, vertebral fracture, neuropathy, total protein level, hypercalcemia, and body mass index, as well as sociodemographic factors, including, race, sex, socioeconomic status, and geographic location. The clinical and laboratory indications were selected based on literature review and clinicians' input. For patients who received SPEP testing, data on these indications within one year before their initial SPEP test were used. For patients who did not receive SPEP testing, these indications were collected within one year of their most recent total protein test. Result: Between 1999 and 2022, 294,640 Veterans were identified, with 17,035 (5.78%) undergoing SPEP testing. Veterans who had SPEP testing were mostly male (77%), White (51%), and frequently obese (BMI>30 kg/m 2) (42%). In addition, 17% of these Veterans who had SPEP testing had neuropathy, 15% had anemia, 11% had chronic kidney disease, 4% had a total protein level > 8.5gm/dL, and 2% had hypercalcemia. Only 0.5% had pathologic fractures and 0.5% had vertebral fractures. VHA providers ordered SPEP tests more often in African American Veterans than White Veterans (OR 1.34, 95% CI 1.29-1.39), and less often in underweight (BMI < 18.5 kg/m 2) Veterans compared to normal-weight (18.5-24.9 kg/m 2) Veterans (OR 0.55, 95% CI 0.40-0.74). SPEP testing was more likely in Veterans having total protein level >8.5gm/dL (OR 3.87, 95% CI 3.47-4.32), vertebral fracture (OR 3.44, 95% CI 2.47-4.81), anemia (OR 3.26, 95% CI 3.06-3.48), hypercalcemia (OR 3.04, 95% CI 2.53-3.65), neuropathy (OR 2.55, 95% CI 2.43-2.69), pathologic fracture OR 2.38, 95% CI 2.38-1.52), and chronic kidney disease (OR 1.97, 95% CI 1.81-2.14) compared to Veterans without the respective indication. Conclusions: VHA providers were likely to order a SPEP for protein level >8.5gm/dL, vertebral fracture, anemia, hypercalcemia, neuropathy, pathologic fracture, and chronic kidney disease. Obesity and demographic factors such as African American race were also associated with SPEP testing. Further research is needed to evaluate the combined influence of these factors on SPEP testing, as well as factors that lead clinicians to order multiple SPEP tests prior to the diagnosis of plasma cell dyscrasias.

B-380 Drift of Freelite on Optilite

Abstract Background Serum free light chains (sFLC) which include kappa (KFLC), lambda (LFLC) and their ratio (K/L) are used for diagnosis and monitoring of plasma cell dyscrasias (PCDs). In 2002, the Binding Site Freelite assay established reference intervals (RIs) for KFLC, LFLC and K/L. Since that time, renal RIs have been proposed and drift for the Freelite assays has been reported. The objective of this study was to evaluate healthy and renal insufficiency population RIs and examine retrospective data to ascertain the reported assay drift. Methods 260 serum samples were measured using the Freelite assay on the Optilite. Creatinine was measured on the Abbott Alinity and eGFR was calculated. Binding Site’s RIs for KFLC, LFLC and K/L were compared to samples with ≥60 eGFR and ≤59 eGFR samples were compared to the hypergammaglobulinemia population from a previous report in 2002. IFE was used to exclude samples with detectable monoclonal proteins. Retrospective data from University Health Network (UHN) was examined. Results The comparison results for the samples are in the tables below: The data suggest that Freelite has drifted up approximately 300% for KFLC, 150% for LFLC and 200% for K/L. Using 220 000 data points from UHN and applying these recalibration factors, the normal KFLC vs LFLC bivariate distribution appears centered to the well-known ‘0.26–1.65’ K/L 100% diagnostic range. Conclusions Drift of Freelite is confirmed with this study and recalibration factors for Freelite are proposed which are lower KFLC values by 300% and lower LFLC values by 150% for K/L to be centered to 0.26–1.65. Institutions should review their data with Freelite on Optilite and any clinical data to confirm this finding. Drift of this magnitude has the potential to cause false positives for kappa and false negatives for lambda in the diagnosis and monitoring of PCDs.

MALDI-TOF-MS for rapid screening analysis of M-protein in serum.

Monoclonal immunoglobin (M-protein) is a serum biomarker for the diagnosis of plasma cell dyscrasias. Despite limitation of analytical sensitivity and resolution, serum protein electrophoresis and immunofixation electrophoresis are still the front-line tests for the detection of M-proteins. Herein, we developed a MALDI-TOF Mass spectrometry-based method for the screening test of M-proteins in human serum. Based on the unique mass signature of different immunoglobin isotypes, M-Proteins could be rapidly identified and typed. The method demonstrated with high analytical performance and throughput, rapid and simple, which could be a new choice for the diagnosis of plasma cell dyscrasias.

MO173: Clinical Profile of Plasma Cell Dyscrasias and Their Renal Outcomes

Abstract BACKGROUND AND AIMS The involvement of kidney in plasma cell dyscrasias is widespread, often referred to as myeloma kidney. At the time of presentation, nearly 50% of patients have renal involvement which is associated with higher mortality [1, 2]. Multiple myeloma is more common in African Americans, with male predilection and median age about 65–70 years [3]. Two major causes of renal insufficiency are light chain cast nephropathy and hyperkalcaemia [4]. Flow cytometry plays an important role in diagnosis of plasma cell dyscrasias. Myeloma cells infrequently express CD19 and variable CD45 in contrast to normal plasma cells. Approximately 70% of myeloma cells will express CD56, which is typically negative in normal plasma cells and in plasma cell leukaemia [5]. Studies addressing the relation of flow cytometry parameters with respect to prognosis and outcome in plasma cell dyscrasias are sparse in Asian population. Hence, this research was conducted to study the clinical profile and correlation of flow cytometry parameters with renal outcomes in patients with plasma cell dyscrasias. METHOD All consecutive patients, aged above 18 years and diagnosed with plasma cell dyscrasias from January 2016 to June 2021 were included. RESULTS Of 165 patients, 115 were males (69.7%), with mean age 58.2 ± 6.4 years. Pallor was seen in 126 (76.4%), bone pains in 90 (54.5%), lytic lesions in 63 (38.2%) and fractures in 37 (22.4%) patients. Severe anaemia (<7 g/ dL) was seen in 35 (21.2%) patients. At presentation, deranged renal parameters with eGFR < 60 mL/min/1.73 m2 were seen in 89 (53.9%) patients, of which 55 (61.8%) patients progressed to chronic kidney disease and 8 (8.9%) patients were continued on maintenance hemodialysis. Nephrotic syndrome presentation was seen in 26 (15.8%) patients. Infections were seen in 65 (39.4%) patients, of which most common infections were respiratory (25, 38.5%), blood stream (18, 27.7%) and urinary tract (12, 18.5%) infections. Serum free light chains were more than 800 mg/L in 71 patients, of them high kappa and lambda levels are seen in 41 (24.8%), and 30 (18.2%) patients, respectively. Most common immunoglobulin seen was IgG (63.6%), followed by IgA (15.8%) and IgE (2.4%). Flow cytometry parameters are shown in Table 1. Remission was attained with chemotherapy in 139 patients (64.3%), and bone marrow transplantation was done in 27 patients (16.4%). Relapse of disease was seen in 31 patients (18.8%) and worsening of renal parameters at relapse was seen in 15 (48.4%) patients. A total of 35 (21.2%) patients expired. Correlation of flow cytometry parameters with renal outcomes showed presence of CD56 with worse renal outcomes (P = .032), and presence of CD117 with favourable renal outcomes (P = .003) with statistical significance. Presence of CD56 and CD138 had increased risk of mortality with significant P value (P = .04, P = .01, respectively). CONCLUSION Flow cytometry parameters may play a role in predicting the prognosis and renal outcomes in patients of plasma cell dyscrasias. Our study showed presence of CD56 with worse renal outcome and mortality, while CD117 presence with favourable renal outcome. Table 1. Flow cytometry parameters in patients with plasma cell dyscrasias CD markers (n = 165) Present Absent CD19 21/165 (12.7%) 144/165 (87.3%) CD38 53/165 (32.1%) 112/165 (67.9%) CD45 46/165 (27.9%) 119/165 (73.9%) CD56 134/165 (81.2%) 31/165 (18.8%) CD117 86/165 (52.1%) 79/165 (48.9%) CD138 46/165 (27.9%) 119/165 (73.9%) KAPPA 93/165 (56.4%) 72/165 (44.6%) LAMBDA 71/165 (43%) 94/165 (57%)

Amyloid deposition in oral cavity and larynx, a single institute experience

Abstract Introduction/Objective Amyloidosis is characterized by extracellular accumulation of insoluble amyloid fibril. Amyloid deposition in the head and neck area is rare. Methods/Case Report In this study, we reviewed 34 specimens from 26 patients including: 18 specimens from the larynx and/or pharynx (13 patients) and 16 specimens from the oral cavity (13 patients). The clinical presentation, related laboratory results, and pathologic finding were reviewed. Results (if a Case Study enter NA) Within the 18 laryngeal specimens were: 10 glottic, 4 supraglottic, 3 nasopharyngeal or pharyngeal wall, and 1 subglottic. Of the 16 cases from oral cavity there were 9 lingual, 3 labial, 2 palatine, 1 tonsillar, and 1 alveolar ridge. Ten out of 13 patients with laryngeal amyloid deposition had protein electrophoresis performed and only 3 of the patients had monoclonal light chain detected. Among these three patients, one had multiple myeloma, one had lymphoplasmacytic lymphoma and one had the diagnosis of plasma cell dyscrasia. Interestingly, in the patients with oral cavity amyloidosis, 10 out of 11 patients tested had abnormal findings. Six of the patients had monoclonal light chain, two demonstrated monoclonal peak of IgG kappa, one with IgG lambda and one with IgA lambda. Among these 10 patients, 6 of them had biopsy-proved or history of multiple myeloma, one patient had marginal zone lymphoma, two patients had systematic amyloidosis. Only one patient did not have any malignancy or systematic involvement identified. Conclusion In our small cohort, the most common location of amyloid deposition in the larynx is glottis. When it involves the oral cavity, tongue is the most common location. Compared to the larynx, amyloid deposition in the oral cavity tends to be associated with hematopoietic malignancy or systematic involvement, although this finding needs to be confirmed by a larger scale of study.

A Comparison of PET-CT to Whole Body Diffusion Weighted MRI in the Diagnosis of Plasma Cell Dyscrasias

IntroductionFunctional imaging techniques such as 18fluoro-deoxyglucose positron emission tomography-computed tomograpthy (PET-CT) and whole body diffusion weighted magnetic resonance imaging with background subtraction (DWIBS) are useful in the detection and enumeration of active disease sites in multiple myeloma (MM). To date few formal comparisons of the two techniques have been performed.MethodsThe ability of PET-CT and DWIBS to determine disease activity defined as focal lesions (FLs) and background bone marrow (BM) abnormalities was studied in82 cases presenting for plasma cell dyscrasia evaluation. All had PET-CT, DWIBS, BM and pertinent laboratory tests performed within 3 days of each other. Using conventional diagnostic criteria, 19 (23%) had MGUS, 7 (9%) SMM, 51 (62%) active MM and 5 (6%) MM in stringent complete response (sCR) defined by IMWG criteria using flow cytometry (sensitivity of 10-5).For both PET-CT and DWIBS, the background BM signal and the presence of FLs were examined. A number of normalization approaches were investigated including comparison of involved areas to the liver, spleen, vertebral bodies and brachial plexus. Reporting radiologists were blinded to the clinical, laboratory and other imaging information. Statistical analysis was performed using R 3.3.1.ResultsBoth PET-CT and DWIBS were able to detect FLs and abnormal diffuse background BM signal. For PET-CT, a BMmax to liver SUVmean ratio of 1.2 or greater best separated cases with active MM from MGUS/SMM and MM in sCR. Of the 51 MM patients, 28 were considered PET-CT positive: 17 with FLs, 1 with diffuse abnormal BM uptake and 10 with both. Using this ratio all SMM and MM in sCR patients were negative. 1/19 MGUS cases were positive with evidence of a FL. A BMmax / liver SUVmean ratio 1.2 or greater therefore had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 55%, 97%, 97% and 57% respectively with regards to correctly categorizing active MM. The other normalization approaches were less specific and less clinically useful as more patients without active MM had higher ratios.For DWIBs, a BM signal greater than or equal to the splenic signal best separated the patient groups. Of the 51 active MM patients, 13 patients had FLs, 10 had diffuse abnormal BM signal, and 10 had both. All SMM patients were negative, one patient with MGUS was found to be positive, and all other non-active MM patients were negative. Therefore the DWIBS criteria of the presence of FLs greater than 1.5 cm, BM signal greater than or equal to spleen, or both, had a sensitivity, specificity, PPV and NPV of 65%, 97%, 97% and 63% respectively.When looking at the overall concordance between the two techniques in 82 cases, 23 patients were positive by both, 42 negative by both and 17 positive with one or other method.Both techniques were able to accurately characterize SMM and MM in sCR. One MGUS was misclassified. The most variation was seen when looking at just MM with active disease (n=51), 23 patients were positive by both and 13 patients negative by both techniques. 15 cases were positive with one or other technique. When comparing the ability of each technique to detect background BM infiltration, a number of cases were noted to be discordant (n=21). More cases were noted to have an abnormal BM infiltration pattern by DWIBS than by PET (n=20 vs 11), suggesting DWIBS is more sensitive at detecting background BM infiltration. DWIBS were also able to detect more FLs than PET, with 12 cases having more lesions on DWIBS than PET-CT. In some instances, however, FLs were seen on the PET-CT and not on the DWIBS (7 cases). When the number of FLs were summarized within ranges, i.e. 0, 1-5, 5-20, >20, PET-CT and DWIBS agreed on focal lesion counts for 63/82 (77%) patients.ConclusionsWhen comparing the ability of PET-CT and DWIBS to detect the different disease patterns (abnormal BM infiltration alone, FLs alone, both abnormal BM infiltration and FLs, or neither), the overall concordance was 53/82 (65%). Although DWIBS had a higher sensitivity for detecting diffuse disease compared to PET-CT, both technologies were at least equal in sensitivity for detecting FLs. This suggests that both modalities are required to accurately detect and describe the imaging features of MM, and that the whole body functional imaging approaches provide complementary approaches for the assessment of plasma cells dyscrasias. DisclosuresDavies:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Morgan:Takeda: Consultancy, Honoraria; Bristol Myers: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding.

Role of clonoSEQ®, a Next-Generation Sequencing (NGS) Assay and PET/CT As a Measure of Minimal Residual Disease Negativity Among Patients with Multiple Myeloma

Role of clonoSEQ®, a Next-Generation Sequencing (NGS) Assay and PET/CT As a Measure of Minimal Residual Disease Negativity Among Patients with Multiple Myeloma

P0307KIDNEY-HEMOPATHY CONSULTATION: A SINGLE-CENTER EXPERIENCE

Abstract Background and Aims Renal involvement in plasma cell dyscrasia has been widely described, including Monoclonal Gammopathy of Renal significance (MGRS). Chronic kidney disease (CKD) in hematological disorders carries major implications for management, prognosis and the potential for progressive renal injury and ESRD. Specific monthly Kidney-Hemopathy Consultation has been created in 2017 in the department of Nephrology. The aimed of this was to describe the clinical, biological and histological characteristics of patients with hematological disorders and CKD. Method From 01/05/2017 to 31/12/2019 adults with hematological disorders and CKD (eGFR<60ml/min and/or proteinuria or hematuria) were prospectively included. Results Fifty-six patients (27 men) were enrolled: Multiple Myeloma (n=30), MGUS (n=11), Lymphoma (n=5), Acute Leukemia (n=4), LMC (n=2), 1 LLC (n=2), Cryoglobulinemia (n=1), Refractory Anemia with Excess blasts (n=1), Bone marrow aplasia (n=1). This nephrology consultation was the first for 22 patients (39%), referred by a hematologist in 38 cases (68%). Renal injury was confirmed after the hematologic diagnosis in 34 patients (61%) and precedes the diagnosis of plasma cell dyscrasia for 8 patients (14%). The median eGFR was 54.1ml/min/1.73m (128-4): CKD stage II (n=16), stage III (n=28), stage IV (n=7) and stage V (n=2). Proteinuria was >0.5g/day for 22 (39.3%) patients including a Bence-Jones proteinuria for 15 patients (27%). Acute Kidney Injury (AKI) was confirmed in 34 patients (63%) and 8 (24%) requiring acute dialysis. Histologic diagnostic of kidney injury was confirmed for 21 patients (38%): 16 kidney biopsies and 5 AL renal amyloidosis confirmed by salivary glands or abdominal fat biopsy. MGRS was confirmed in 34 patients (61%): Cast nephropathy (n=10;29%), AL amyloidosis (n=7;20%); C3 nephropathy (n=3; 9%), Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Deposits (n=3), Light Chain Proximal Tubulopathy (n=3), Randall-type monoclonal immunoglobulin deposition disease (n=2, 6%), 1 Minimal Change Disease (n=1; 3%), Glomerulonephritis with Organized Microtubular Monoclonal Ig Deposits (n=1) and exclusive tumoral renal infiltration (n=1). Associated tumoral infiltration or crystalline podocytopathy was confirmed in 2 and 1 biopsy respectively. Glomerular MGRS was highly suspected for 2 patients, even if no biopsy was performed. MGRS was excluded for 22 patients (39%): AKI due to antibiotics or sepsis (n=8; 36%), hypovolemia (n=4; 18%) or hypercalcemia (n=3; 14%); 2 renal artery stenosis due to tyrosine kinase inhibitors (n=2; 9%), nephroangiosclerosis (n=1), lithiasis (n=1), CKD post- nephrectomy CKD (n=1), and immunoallergic nephritis (n=1). Hematological treatment was initiated in 54 patients (96%). All patients with MGRS were treated, whom 17 (50%) completely or partially in the Nephrology department. Proteasome inhibitors, alkylant agents and IMIDs were the main molecule used in first line therapy (56%, 23% and 12% respectively). Eleven patients (20%) had stem cell transplantation. After a median follow up of 16 months (38-0), complete or very good partial hematologic response was obtained in 48 patients (89%); whom 30 with MGRS (88%). Median eGFR was 45ml/min/1.73m (142-4): CKD stage II (n=18), stage III (n=23) and stage IV (n=9). Only 1/3 CKD stade V patient needed chronic replacement therapy. Eight patients died (14%): 4 uncontrolled hematologic disease (50%) and 3 septic complications (38%). Conclusion Very closed collaboration between Nephrology and Hematology Department in our Center contributes to improve early management of patients with hematological disorders associated with CKD, and probably their survey. Hemato-Nephrology is a viable and emergent specialty.

The Utilization of Screening Tests for Plasma Cell Dyscrasias By Internal Medicine Physicians at a Teaching Hospital

Background. Plasma cell Dyscrasias (PCD) are a spectrum of monoclonal gammopathies which result from proliferation of plasma cells that produce an immunologically homogeneous protein known as M-protein. PCDs include monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), multiple myeloma (MM), Waldenstrom's macroglobulinemia (WM), primary amyloidosis (AL), plasmacytoma, light chain deposition disease (LCDD) and POEMS syndrome. Screening for gammopathy is usually done by serum protein electrophoresis (SPEP) with immunofixation (IFE), serum free light chains (FLC) and urine protein electrophoresis (UPEP) with immunofixation. Except for low risk MGUS, early diagnosis can have a significant impact on the clinical outcome of PCD. Thus, accurate and timely screening for early diagnosis is crucial. In this study, we aim to evaluate the screening process for plasma cell dyscrasias in a teaching hospital by targeting internal medicine physicians including primary care physicians. Methods: We retrospectively reviewed charts of 2532 patients who had undergone PCD screening tests at Truman Medical Center (TMC), the primary teaching hospital for University of Missouri-Kansas City (UMKC). The studied data was from two blocks of time: 2011-2012 and 2017-2018. Only patients who were >18 years of age and who had any of these screening tests done for the very first time during the study period were included. Patients who had tests done outside of the study period or had prior similar testing or known diagnosis of PCD were excluded. Data was collected to assess if screening tests had been ordered appropriately by internal medicine physicians. Appropriate screening was defined as a screening that had SPEP along with IFE and FLC. We compared internal medicine physicians' utilization of these tests between two different time frames 1/1/2011-12/31/2012 versus 1/1/2017-12/31/2018. Results: A total of 2532 patients were reviewed. 1076 were included with a mean age of 57.4 years. Population demographic is detailed in Table 1. Most of the PCD screening tests were ordered in the outpatient setting (67%). The three most common indications for testing were workup of chronic kidney disease, abnormal serum protein levels and neuropathy (Figure 1). Outcomes of screening tests are shown in Figure 2. Majority of these tests were ordered by internal medicine physicians (42%) followed by nephrology (19%) and hematology-oncology services (10%). Internal medicine ordered 448 tests overall. During 2011-2012 they screened 211 patients. Out of these, 199 had SPEP, 19 had IFE, 68 had UPEP and 23 patients had FLC ordered on initial screening. Only 18 patients (8.5%) were screened appropriately. Between 2017-2018, a total of 237 patients were screened by internal medicine physicians. Among them 231 had SPEP, IFE was checked by automatic reflex (a new feature added by our lab in 2013) in 138 patients, UPEP was ordered 67 times and 48 patients had FLC checked with 45 patients (19%) screened appropriately. Conclusion : Screening for plasma cell dyscrasias is frequently done by physicians from specialties other than hematology-oncology. Ordering an appropriate set of tests including FLC in addition to SPEP with IFE is imperative at time of initial screening. Our study showed that internal medicine physicians order most of the intial testing for PCD, however they often miss incorporating FLC as part of their screening for PCD. This could potentially lead to missing some cases and delay in timely diagnosis. Although there has been improvement in ordering appropriate screening, but proper measures should be undertaken to increase the efficacy of screening for PCD. Disclosures No relevant conflicts of interest to declare.

Flow Cytometric Evaluation of Traditional and Novel Surface Markers for the Diagnosis of Plasma Cell Dyscrasias.

Increasing interest has been expressed for flow cytometric immunophenotyping for diagnosis and monitoring in plasma cell dyscrasias over the last decades. The aim of this investigation was to compare the expression strength of various cell surface markers used traditionally or currently under investigation on normal and abnormal PC populations. We enrolled 295 consecutive patients undergoing bone marrow aspiration in the workup of monoclonal gammopathies, selecting 54 normal and 241 abnormal PC populations via flow cytometry to characterize the expression of CD45, CD38, CD138, CD19, CD56, CD20, CD27, CD28, CD81, CD117 and CD200 on the cell surface of PCs. We observed significant differences in the expression strength of all assessed markers between normal and abnormal PC populations in all markers except for CD20. While none of them was conclusive on its own, the combination of CD81 positivity and CD117 negativity was present in 98.1% of normal PC populations tested. In contrast, particularly CD117 positivity, but also CD81 negativity was indicative of an abnormal PC phenotype. Our results highlight the descriptive value of CD81 and CD117 for the allocation of bone marrow PCs to a normal or abnormal phenotype.

Application Value of CD138 MACS-FISH in the Genetic Diagnosis of Plasma Cell Dyscrasia

To investigate the cytogenetic characteristics of the various plasma cell dyscrasia using the CD138 MACS-FISH, to elucidate the application value of MACS-FISH in the genetic diagnosis of plasma cell dyscrasia, and to explore the standardization of FISH detection for plasma cell dyscrasia. A total of 232 patients with newly diagnosed plasma cell dyscrasia were collected, including 203 cases of MM, 24 cases of AL amyloidosis and 5 cases of MGUS, whose cytogenetic abnormalities were detected by MACS-FISH, and the differences of the positive detection rates of chromosome karyotype analysis, C-FISH and MACS-FISH in MM cytogenetic abnormality were compared. The sensitivity of C-FISH and MACS-FISH were analyzed and compared according to the proportion of bone marrow plasma cells. The correlation between the positive cell rates of C-FISH and MACS-FISH and the proportion of plasma cells were analyzed respectively. The differences in the clone size detected by C-FISH and MACS-FISH were compared. The incidence of cytogenetic abnormality of MM, AL amyloidosis and MGUS detected by MACS-FISH were 85.9%, 62.5%, 60%, respectively. The incidence rate of MM cytogenetic abnormality detected by Chromosome karyotype analysis and C-FISH were 20.0% and 64.7%, respectively, which were significantly lower than that of MACS-FISH(P<0.001). The positive rate of 14q32 translocation, del(14q32), t(11;14), +17p13 and the coexistence of 2 and ≥3 kinds of cytogenetic abnormalities detected by MACS-FISH were significantly higher than that detected by C-FISH(P<0.05). When the plasma cell ratio was less than or equal to 5%, the positive detection rate of MACS-FISH was significantly higher than that of C-FISH (P=0.001), and there was no significant difference in different plasma cell proportion group of MACS-FISH. However, when the plasma cell ratio was less than or equal to 5%, the positive detection rate of C-FISH detection was significantly lower than that of the other 3 groups (P=0.013,P=0.001,P<0.001). The positive cell rates of all cytogenetic abnormalities in C-FISH group and +1q21 and 14q32 translocation in MACS-FISH group were significantly positively correlated with the proportion of plasma cells(P<0.05). The clone size of various cytogenetic abnormalities in MACS-FISH group were significantly higher than that in C-FISH group(P<0.001). MACS-FISH may significantly enhance the detection rate of cytogenetic abnormalities in various plasma cell dyscrasia, and it can better reflect the cytogenetic abnormality of plasma cell dyscrasia and its clone size. MACS-FISH may be recommended as a standard method for the genetic diagnosis of plasma cell dyscrasia, the risk stratification of MM and SMM, as well as the genetic diagnosis and research of MGUS and AL amyloidosis.

Concurrent De Novo Myeloid Neoplasm and Plasma Cell Dyscrasia: A Clinicopathologic Study of 27 Cases

Background: Myeloid and plasma cell neoplasms represent clonal disorders of different lineages. Patients with plasma cell dyscrasia (PCD) may develop secondary myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) following cytotoxic chemotherapy for PCD. Therapy-related MDS/AML has a poor prognosis and is clonally distinct from the PCD. Coexistence of de novo MDS/AML and PCD without prior chemotherapy has only occasionally been reported in the literature. Whether these two distinct neoplasms are derived from the same ancestral pre-malignant stem cell is uncertain. In this study, we report 27 cases of concurrent MDS/AML and PCD, and summarize the clinicopathologic features.Methods and Materials: Twenty-seven cases of untreated smoldering MM (SMM) or monoclonal gammopathy of undetermined significance (MGUS) with concurrent de novo MDS, AML or myelodysplastic/myeloproliferative neoplasm (MDS/MPN) were identified from the pathology database at the Department of Hematopathology, Moffitt Cancer Center between 2005 and 2014. Bone marrow biopsies, laboratory data, flow cytometric and cytogenetic studies of each case were reviewed. Clinical features were obtained by chart review.Results: There were 20 (74%) males and 7 females (26%) with a median age of 71 (range, 57 -87) years. Twenty-two (81%) patients had a diagnosis of MDS/AML made at the same time as the diagnosis of PCD. Four (15%) patients had a history of MGUS ranging from 6 months to 20 years and received no treatment. One (4%) patient had a history of low grade MDS/refractory cytopenia with multilineage dysplasia (RCMD) for 7 years before the development of PCD. None of the patients received prior cytotoxic chemotherapy, radiotherapy or immunomodulatory therapy before the concurrent neoplasms were diagnosed. Thirteen (48%) patients were diagnosed with MGUS, and 14 (52%) patients were diagnosed with SMM. Four patients with MGUS evolved to SMM and none of the patients with MGUS or SMM showed progression to symptomatic MM. The myeloid neoplasms included MDS (n=17, 63%), AML (n=6, 22%), chronic myelomonocytic leukemia, type 1 (CMML-1: n=3, 11%), and refractory anemia with ring sideroblasts associated and thrombocytosis (RARS-T: n=1, 4%). The MDS cases were 1 case of MDS with isolated del(5q) (4%), 2 cases of RARS (7%), 10 cases of RCMD, (37%), 1 case of refractory anemia with excess blasts, type 1 (RAEB-1, 4%), and 3 cases of RAEB-2 (11%). Twenty-five patients (93%) received therapy for the myeloid neoplasms, including DNA hypomethylating agent(s) (HMA) and/or combination chemotherapy. Of them only 2 patients were treated for PCD. Excluding 6 patients with AML, 10 of 19 patients with MDS or MDS/MPN have full or partial response to HMA therapy. However, the remaining 9 patients showed disease progression. Two patients with low grade MDS had progression to RAEB-1, while 6 patients (3 RAEB I or II and 3 RCMD) had progression to AML. The patient with RARS-T showed sequential progression of disease to CMML and AML. Two of the three patients with CMML-1 showed progression of disease to CMML-2, but without further progression to AML. The median duration of follow up was 20 (range, 2 – 143) months, and 9 patients (33%) died of the disease, and one patient died from concurrent lung cancer. Of the 17 patients with MDS, 76% were categorized as low/intermediate-1 risk and 24% were intermediate-2 or high risk according to the International Prognostic Scoring System (IPSS). Based on the IPSS risk score, the median overall survival (OS) was 23, 24, 20, and 13 months for low, intermediate-1, intermediate-2, and high-risk categories, respectively. There were no differences in the OS rates. The 5-year OS rate of the 13 patients with low/intermediate-1 risk MDS was 62%.Conclusion: Based on the review of over 1000 myeloid neoplasms registered at our institutional pathology database during the time period, the concurrent de novo MDS/AML and PCD is considered an uncommon occurrence but represents an important clinical entity. A subpopulation of patients with low grade MDS tended to have a rapid disease progression, while the SMM cases remained indolent without progression to symptomatic MM. Excluding an underlying myeloid disorder has therapeutic implication in a patient with otherwise MGUS /SMM and cytopenias without bone or renal disease. DisclosuresNo relevant conflicts of interest to declare.

Primary amyloidosis-induced nail dystrophy

Primary amyloidosis is caused by a monoclonal proliferation of plasma cells and is capable of producing cutaneous lesions. A 56-year-old male was admitted to the hospital for evaluation of chronic back pain and acute lower extremity weakness. On examination, he was noted to have subungual verrucous plaques with overlying nail dystrophy on his bilateral thumbs. A biopsy of one subungual lesion showed a deposition of amorphous material in the dermis that stained with Congo red and crystal violet. These cutaneous lesions ultimately led to the diagnosis of plasma cell dyscrasia and primary amyloidosis. Based on the literature search, primary amyloidosis presenting with this degree of subungual thickening and overlying nail dystrophy has not been previously reported.

Multiclonality In Multiple Myeloma: A Retrospective Analysis Of Clonal Progression and Selection

IntroductionGenomic instability and multiclonality is the hallmark of many cancers including multiple myeloma (MM). Genetic alterations and clonal prominence occur over time as patients undergo various treatment modalities and can be followed by examining factors such as copy number abnormalities. Occasionally more than one monoclonal spike is noted on the serum protein electrophoresis (SPEP) indicating the existence of several distinct populations of clonal plasma cells producing a measurable amount of monoclonal (M) protein. Using routinely measureable clinical assays, SPEP and serum free light chains (SFL), we set out to identify the prevalence of multiclonality in patients with plasma cell dyscrasia, and to examine the natural history and effect treatment practices have on clones over time. MethodsWe retrospectively identified adult patients who were registered with the London Regional Cancer Program (LRCP), a tertiary care referral center in London, Ontario, Canada, since 2000 with a diagnosis of monoclonal gammopathy of uncertain significance (MGUS), smoldering myeloma, multiple myeloma or solitary plasmacytoma. Our current SPEP quantitation method has been in use since September 2004, so these SPEP results of patients identified from our initial search were examined for evidence of multiple monoclonal peaks as a surrogate marker for multiclonality. Inclusion criteria required a new diagnosis of plasma cell dyscrasia since the year 2000 and biclonal/multiclonal M protein peaks on SPEP followed through the LRCP. Demographics, SPEP results, treatment modalities and last recorded follow up or death for these patients was recorded. Outcome measures included quantification of complete remission, partial remission, very good partial remission and no response following systemic therapy to look for concordance in clone response. ResultsSince 2000, 1402 patients met the inclusion criteria; 144 patients met our surrogate criteria for multiclonality, representing a prevalence of approximately 10%. The majority of patients had MGUS (58, 40.3%) or MM (70, 48.6%) at first identification. Of these patients, 96 (66.7%) were male and the average age at diagnosis was 65.9 years. 58 (40.3%), primarily with MGUS, had no treatment and thus cannot be examined for treatment selective pressures. The number of clones identified ranged from two (114, 79.2%) to five. 62 (43.1%) had clones that were of similar immunoglobulin and light chain subtype, and half of patients had multiple clones identified at the same time point compared with development of clones during follow up investigations.In order to examine for concordance in treatment response between clones, we required that clones have a pre- and post- treatment value and have received systemic therapy with a measurable nadir. Only 26 patients had values that met these criteria, mainly due to clones disappearing with time, including 7 patients with no treatment, or oral treatment without recurrence and thus not quantifiable for comparison. Of these 26, approximately half showed discordance between clones, even in those with clones of the same M protein subtype. Of note, 4 discordant patients initially showed the same response to treatment and later developed divergent responses. DiscussionMulticlonality in plasma cell neoplasms is a common occurrence, with a prevalence of 10% in our patient population. The use of SPEP and SFL as surrogate markers for multiclonality likely underestimates the true prevalence of multiple clones measured by genetic methods due to insensitivity to resolved non secretory clones or multiple clones secreting similar immunoglobulin. As seen in previous studies, our results demonstrate that plasma cell clone response can diverge over time, potentially spontaneously or as a result of selection pressures imposed by therapy. These findings may help direct therapy and suggests prognosis as clonal divergence could herald genetic changes associated with therapy resistant disease. Disclosures:No relevant conflicts of interest to declare.

Extensive Amyloid Deposit in Bone Marrow Aspirate

A 62-year-old female presented in the Hepatology OPD with progressive weakness, loss of appetite and dyspnoea. On examination she had icterus, anasarca and hepatomegaly. The liver was enlarged 8 cm below the right costal margin and hard on palpation with vague nodularity. There was no splenomegaly or lymphadenopathy. She was a known case of hypothyroidism. X-ray chest showed bilateral pleural and pericardial effusion. Echocardiography was suggestive of restrictive cardiomyopathy. MRI showed hyperintensity of liver on T2. Liver function tests were deranged. Kidney function tests were normal. Complete hemogram showed Hb of 11 gm/dl, total leukocyte count 7.8 × 109/L and platelets were 178 × 109/L. Liver biopsy performed for the workup revealed extensive amyloid deposit in the vessels and the sinusoids near completely replacing hepatic parenchymal cells. Endoscopic biopsies from duodenum and rectum showed amyloid deposition in blood vessels. Serum and urine electrophoresis and immunofixation did not showed monoclonal M band. Serum Ig-free light chain showed κ to λ ratio of 4.12 (normal 0.26–1.65) and β2 microglobulin was raised. Bone marrow aspirate and biopsy was performed to rule out multiple myeloma. Aspirate showed hypocellular marrow particles with extensive deposits of blue-pink acellular amorphous (Fig. 1A, B) extracellular congophilic material (Fig. 1C) displaying green bireferingence under polarised light. There was mild erythroid hyperplasia with adequate representation of myeloid and erythroid series of cells with normal maturation and no dysplastic changes. The plasma cells were approximately 6 % out of 500 cell count. A few isolated small aggregates of 4–6 plasma cells were also seen. Bone marrow biopsy also revealed homogenous pale eosinophilic acellular deposits of amyloid in the interstium and vessel walls (Fig. 1D). Plasma cell group or nodules were not seen. Immunohistochemistry for kappa and lambda was performed on the bone marrow biopsy which showed plasma cells showing positivity predominantly for kappa and focally for lambda. A final clinico-pathological diagnosis of plasma cell dyscrasia with AL (kappa) systemic amyloidosis was made. Fig. 1 Bone marrow aspirate showing extensive deposits of blue-pink acellular amorphous extracellular material (A, B) congophilic with congo red stain (C). Bone marrow biopsy also revealed homogenous pale eosinophilic acellular deposits of amyloid in the interstium ... Primary or AL amyloidosis is the commonest cause of systemic amyloidosis worldwide [1,2]. Bone marrow examination in these cases is performed in order to evaluate plasma cell infiltration. Plasma cells may be increased to the level of overt multiple myeloma or the number could be <10 % in which case it is classified as plasma cell dyscrasia or monoclonal gammopathy of unknown significance (MGUS). Amyloid is usually is not seen or is very sparse if present in aspirate, however biopsy usually shows amyloid deposition on vessel wall and rarely in interstitium [3]. In a study by Swan et al. the bone marrow core biopsy demonstrate amyloid deposition in 60 % cases out of 100 biopsies of patients with AL (primary) amyloidosis studied [2]. In their series plasma cell dyscrasia was observed in 83 cases with majority of lambda (65 cases) light chain disease. They also observed that interstitial amyloid deposition was significantly more commonly associated with patients with a monoclonal kappa light chain gammopathy, like in our case. Few studies have shown mean plasma cell percentages ranging from 7 to 14 % by analyzing the bone marrow core biopsy specimen in AL amyloidosis using immunohistochemical stains for light chain immunoglobulins [2, 4]. However, the finding of extensive bone marrow amyloid deposition in the aspirate smears is very unusual and rarely reported to the best of our knowledge.

Rheumatic masks of plasma cell dyscrasias

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CD81: A Novel, Specific and Highly Sensitive Marker in Flow Cytometric Diagnosis of Plasma Cell Dyscrasia

Abstract 2880 Background:The percent abnormal plasma cells (aPC) as determined by flow cytometry (FC) has been shown to be an independent risk factor for progression from myeloma precursor disease (monoclonal gammopathy of uncertain significance, MGUS; smoldering multiple myeloma, SMM) to multiple myeloma (MM). However, differentiation of aPCs from normal PCs (nPCs) in these patients is challenging. MM cell lines are know to underexpress the tetraspanin proteins (e.g. CD81, CD82) in comparison to nPCs. Although CD81, a nonglycosylated tetraspanin, is robustly expressed on the surface of nPCs, little information is available regarding its expression in the aPCs of MM, SMM and MGUS. In this study we evaluate the expression of CD81 in conjunction with CD19, CD45 and CD56 in bone marrow aPCs and nPCs from patients with MM, SMM and MGUS. Methods:Bone marrow aspirates from 41 patients (9 MGUS, 22 SMM, 7 MM, 3 non-neoplastic with clinical suspicion of MGUS) were analyzed with 8-color multiparametric FC using a panel of antibodies (CD138, CD38, CD19, CD20, CD27, CD28, CD45, CD56, CD81, CD13, CD14, CD16, CD3, CD34 and intracellular kappa & lambda light chains). The pattern of surface antigen and intracellular light chain expression was utilized to determine the percent aPC (defined as monoclonal with aberrant antigen expression) and percent nPC (defined as polyclonal with normal antigen expression). In all cases the pattern of antigen expression was evaluated in the aPCs; additionally, in cases with greater than 5% nPCs (19/41 patients: 8 MGUS, 8 SMM and 3 non-neoplastic) the pattern of antigen expression was evaluated in the nPCs. The ability to detect clonal aPC by evaluation of FC pattern of antigen expression was determined and compared for CD19, CD45, CD56 and CD81. We also examined the sensitivity and specificity of the CD19 and CD81 combination verses the conventional combination of CD19, CD56 and CD45 (Perez-Persona et al, Blood 2007) for the detection of clonal aPC. Results:CD81 was strongly expressed by nPC (average mean fluorescent intensity (MFI): 11500, standard deviation (SD): 5061, range: 5347–21657) in contrast to aPC with abnormally weak expression (average MFI: 1487, SD: 887, range: 647–4311). CD81 was a highly reliable marker for the detection of clonal PC; with 90% sensitivity and 100% specificity. It was the most specific and second most sensitive marker in our study (Table 1). CD81 was equally sensitive in detection of aPCs in MGUS, SMM and MM. Evaluation of the combined pattern of expression of CD19 and CD81 resulted in 100% sensitivity and 100% specificity for detection of aPC, which is greater than the conventional combination of CD19, CD56 and CD45, yielding 100% sensitivity but 90% specificity, for diagnostic evaluation of aPC. Conclusions:CD81 is a highly reliable marker in the detection of abnormal plasma cells in MM, SMM and MGUS. The combined approach of CD19 and CD81 is superior to other conventional marker combinations (i.e. CD19, CD45, and CD56) in terms of detection of clonal plasma cells and may replace their use in the clinical evaluation of bone marrow aspirates for plasma cell processes. Furthermore, it should help widening the applicability of minimal residual disease testing in MM.Table 1Sensitivity and specificity of different flow cytometric markers in the detection of malignant plasma cells.Sr NoMarkerSensitivitySpecificity1CD8190%100%2CD19100%84%3CD5668%90%4CD4576%53%5CD2779%95%6CD2824%100%7CD2024%90% Disclosures:No relevant conflicts of interest to declare.

Serum free light chain analysis in multiple myeloma and plasma cell dyscrasias

After the development of a reliable method to detect free light chains in serum, several investigations have been conducted to explore their importance in plasma cell dyscrasias (PCD). Detection of monoclonal proteins is very important in the diagnosis and management of PCD, which include a broad spectrum of diseases such as multiple myeloma and also benign, premalignant disorders like monoclonal gammopathy of undetermined significance. The aim of this article is to summarize the recent studies and to highlight the importance of free light chain analysis in the diagnosis of PCD, its prognostic value and role in the management of this group of diseases.